Second Life viewer sources 1.21.0-RC

1 files changed, 182 insertions, 0 deletions

diff --git a/linden/indra/llrender/llrendersphere.cpp b/linden/indra/llrender/llrendersphere.cpp
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+++ b/linden/indra/llrender/llrendersphere.cpp
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+/** 
+ * @file llrendersphere.cpp
+ * @brief implementation of the LLRenderSphere class.
+ *
+ * $LicenseInfo:firstyear=2001&license=viewergpl$
+ * 
+ * Copyright (c) 2001-2008, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+//      Sphere creates a set of display lists that can then be called to create 
+//      a lit sphere at different LOD levels.  You only need one instance of sphere 
+//      per viewer - then call the appropriate list.  
+
+#include "linden_common.h"
+
+#include "llrendersphere.h"
+#include "llerror.h"
+
+#include "llglheaders.h"
+
+GLUquadricObj *gQuadObj2 = NULL;
+LLRenderSphere gSphere;
+
+void drawSolidSphere(GLdouble radius, GLint slices, GLint stacks);
+
+void drawSolidSphere(GLdouble radius, GLint slices, GLint stacks)
+{
+        if (!gQuadObj2)
+        {
+                gQuadObj2 = gluNewQuadric();
+                if (!gQuadObj2)
+                {
+                        llwarns << "drawSolidSphere couldn't allocate quadric" << llendl;
+                        return;
+                }
+        }
+
+        gluQuadricDrawStyle(gQuadObj2, GLU_FILL);
+        gluQuadricNormals(gQuadObj2, GLU_SMOOTH);
+        // If we ever changed/used the texture or orientation state
+        // of quadObj, we'd need to change it to the defaults here
+        // with gluQuadricTexture and/or gluQuadricOrientation.
+        gluQuadricTexture(gQuadObj2, GL_TRUE);
+        gluSphere(gQuadObj2, radius, slices, stacks);
+}
+
+
+// lat = 0 is Z-axis
+// lon = 0, lat = 90 at X-axis
+void lat2xyz(LLVector3 * result, F32 lat, F32 lon)
+{
+        // Convert a latitude and longitude to x,y,z on a normal sphere and return it in result
+        F32 r;
+        result->mV[VX] = (F32) (cos(lon * DEG_TO_RAD) * sin(lat * DEG_TO_RAD));
+        result->mV[VY] = (F32) (sin(lon * DEG_TO_RAD) * sin(lat * DEG_TO_RAD));
+        r = (F32) pow(result->mV[VX] * result->mV[VX] + result->mV[VY] * result->mV[VY], 0.5f);
+        if (r == 1.0f) 
+        {
+                result->mV[VZ] = 0.0f;
+        }
+        else
+        {
+                result->mV[VZ] = (F32) pow(1 - r*r, 0.5f);
+                if (lat > 90.01)
+                {
+                        result->mV[VZ] *= -1.0;
+                }
+        }
+}
+
+void lat2xyz_rad(LLVector3 * result, F32 lat, F32 lon)
+{
+        // Convert a latitude and longitude to x,y,z on a normal sphere and return it in result
+        F32 r;
+        result->mV[VX] = (F32) (cos(lon) * sin(lat));
+        result->mV[VY] = (F32) (sin(lon) * sin(lat));
+        r = (F32) pow(result->mV[VX] * result->mV[VX] + result->mV[VY] * result->mV[VY], 0.5f);
+        if (r == 1.0f) 
+                result->mV[VZ] = 0.0f;
+        else
+        {
+                result->mV[VZ] = (F32) pow(1 - r*r, 0.5f);
+                if (lat > F_PI_BY_TWO) result->mV[VZ] *= -1.0;
+        }
+}
+
+// A couple thoughts on sphere drawing:
+// 1) You need more slices than stacks, but little less than 2:1
+// 2) At low LOD, setting stacks to an odd number avoids a "band" around the equator, making things look smoother
+void LLRenderSphere::prerender()
+{
+        //  Create a series of display lists for different LODs
+        mDList[0] = glGenLists(1);
+        glNewList(mDList[0], GL_COMPILE);
+        drawSolidSphere(1.0, 30, 20);
+        glEndList();
+
+        mDList[1] = glGenLists(1);
+        glNewList(mDList[1], GL_COMPILE);
+        drawSolidSphere(1.0, 20, 15);
+        glEndList();
+
+        mDList[2] = glGenLists(1);
+        glNewList(mDList[2], GL_COMPILE);
+        drawSolidSphere(1.0, 12, 8);
+        glEndList();
+
+        mDList[3] = glGenLists(1);
+        glNewList(mDList[3], GL_COMPILE);
+        drawSolidSphere(1.0, 8, 5);
+        glEndList();
+}
+
+void LLRenderSphere::cleanupGL()
+{
+        for (S32 detail = 0; detail < 4; detail++)
+        {
+                glDeleteLists(mDList[detail], 1);
+                mDList[detail] = 0;
+        }
+        
+        if (gQuadObj2)
+        {
+                gluDeleteQuadric(gQuadObj2);
+                gQuadObj2 = NULL;
+        }
+}
+
+// Constants here are empirically derived from my eyeballs, JNC
+//
+// The toughest adjustment is the cutoff for the lowest LOD
+// Maybe we should have more LODs at the low end?
+void LLRenderSphere::render(F32 pixel_area)
+{
+        S32 level_of_detail;
+
+        if (pixel_area > 10000.f)
+        {
+                level_of_detail = 0;
+        }
+        else if (pixel_area > 800.f)
+        {
+                level_of_detail = 1;
+        }
+        else if (pixel_area > 100.f)
+        {
+                level_of_detail = 2;
+        }
+        else
+        {
+                level_of_detail = 3;
+        }
+        glCallList(mDList[level_of_detail]);
+}
+
+
+void LLRenderSphere::render()
+{
+        glCallList(mDList[0]);
+}